GB287474A - Improvements in or relating to carburetors for internal combustion engines - Google Patents

Abstract

287,474. Stromberg Motor Devices Co., (Assignees of Mock, F. C., and Chandler, M. E.). March 21, 1927, [Convention date]. Spray carburettors. - A supplementary fuel well, open to the atmosphere and fed from the float chamber through a valve-controlled orifice, is adapted to supply additional fuel when the engine is cold, the supply of additional fuel rapidly decreasing as the engine speed increases. The supplementary well 32, Figs. 5 and 7, is fed from the float chamber 21 through a conduit 35 and an orifice 34 controlled by a spring-loaded valve 36, and is provided with a vent 33. The well 32 is connected by a conduit 49 to a nozzle. 50 opening into a primary Venturi tube 19 adjacent the outlet of the main fuel nozzle 18, and by a conduit 51 and orifice 51<1>, situated below the normal fuel level, to an annular well 52 communicating with the slow-running conduit 53 through orifices 54 situated above the normal fuel level. Fuel is supplied from the float chamber to the chamber 28 beneath the main nozzle 18 through a well the outlet of which is controlled by a manually-operated needle valve, and passes through orifices 58, Fig. 3, in the main nozzle, an annular chamber 57, and a conduit 56, to the slow-running conduit 53. The conduit 53 opens into a passage 59 provided with an air inlet 62 controlled by a valve 63, and restricted outlets 60, 61 adjacent the throttle valve 14. The valve 36 is operated by a bellcrank lever 39, the arm 44 of which is adapted to be engaged by a roller carried by an arm on the spindle 47 of the air valve 12, the valve 36 closing as the air valve opens and vice versa. When the valve 36 is closed the well is gradually emptied, and air drawn in through the vent 33 passes, according to the setting of the throttle valve, either to the slow-running conduit 53 or to the nozzle 50. In a modification, the valve 36 is controlled by a bimetallic strip heated by the engine and adapted to open the valve when the engine is cold. Fuel for accelerating is supplied to a nozzle 75, Fig. 4, in the choke tube 19, from a vented well 70 fed from the float chamber through a conduit 72, and containing a tube 71 communicating through a restricted orifice 74 with the induction pipe above the throttle valve 14, the fuel drawn into the tube 71 by suction when the throttle is nearly closed being supplied through the nozzle 75 when the throttle is opened. To aerate the fuel supplied by the main nozzle 18, the nozzle is provided with orifices 78, Fig. 4, which communicate with a conduit 79 to which air is admitted through a restricted orifice 80 and through an inlet 82 controlled by a valve 81 operated by an arm 86 on the spindle 15 of the throttle valve 14. The valve 81 is open during normal running, but is closed when the throttle valve is fully open for high speed or full power.